Intervalometer



April 3, 1962 s. BAYLEY ETAL INTERVALOMETER 3 Sheets-Sheet 1 Filed May 12, 1950 R n 5 RH M .w E k LE Yr m m r WW5 4 M L p 5 C April 3, 1962 D. s. BAYLEY ET AL 3,027,808

INTERVALOMETER Filed May 12, 1950 3 Sheets-Sheet 2 M 228 D MD S Z EEE O Z50 PH/L/P 41 H/TE 23 By C421. F c an-1? Lsam April 3, 1962 D. s. BAYLEY ETA]. 3,027,808

INTERVALOMETER Filed May 12, 1950 5 Sheets-Sheet 3 JNVENTORS 442 NHLD .5, Ben

lL/P WH/T BY Cam. f-T SCHHEFER MLSQMM 3,%Z?,8b8 Patented Apr. 3, 1952 3,027,388 INTERVALQMETER Donaid S. Eayley, Redford Village, Phiiip A. White, White Piains, and Carl F. Schaefer, Port Viashington, N.Y., assignors, by mesne assignments, to United Aircraft Klorporation, East Hartford, Conn., a corporation of Delaware Filed May 12, 1950, Ser. No. 161,634 Claims. (Cl. 891.5)

Our invention relates to intervalometers, and more particularly to a device to determine the bomb spacing, that is, the distance between adjacent bombs in a stick dropped from a bombing aircraft and simultaneously determining automatically the stick length.

The intervalometers of the prior art comprise chiefly timing devices which determine the times at which successive bombs of a stick are dropped. These devices require additional means for determining the stick length which must be used as a function in computers for calculating the proper time for the release of the bombs.

One object of our invention is to provide an intervalometer in which the number of bombs to comprise a stick may be varied within wide limits and in which the bomb spacing, that is, the distance between the bombs at the point of impact on the ground, may likewise be varied and in which the individual bombs comprising the stick are automatically dropped as a function of the ground speed of the aircraft and of the predetermined ground spacing. The number of bombs to be dropped, less one, multiplied by the spacing between the bombs on the ground, determines the length of the stick. Onehalf of the stick length is the release advance distance at which the first bomb is to be dropped, and this informa tion is necessary as an input to the computer.

Another object of our invention is to provide an intervalometer in which the setting of the number of bombs to comprise the stick, and the bomb spacing automaticaily compute the release advance as a positional indication which may be fed to the computer.

Other and further objects of our invention will appear from the following description.

In general, our invention contemplates the provision of a housing in which is disposed a drum having a pair of sun gears adjacent each end. A plurality of planetary gears which are interconnected by rods mesh with the sun gears. Coaxially with the axis of the drum We provide a shaft carrying a plurality of gears of progressively decreasing diameter. A shaft extending parallel to the axial shaft and carried by the sun gears supports a plurality of gears of progressively increasing diameter. All of the gears except the first on the coaxial shaft are carried for relative rotation with the shaft. All of the gears on the parallel shaft are secured to the shaft for rotation therewith. The gear ratios are such that the movement of a control knob to set the spacing between the first bomb and the second bomb of the stick automatically adjusts all of the other gears as multiples of the spacing. The positioned gears carry radialiy extending arms secured to the rods interconnecting the planetary gears such that these will be positioned at uniform distances from each other around the sun gears, which spacing may be readily varied. The rods positioned by the planetary gears control the bomb releasing mechanism to drop the bombs. The number of bombs which are to comprise the stick may likewise be readily set. The above mechanism comprises a plurality of cams in connection with which we provide a rotary cam operated intervalometer switch adapted to be driven as a function of the ground speed. This switch is adapted to close a circuit to release the bombs at the predetermined intervals. When the desired number of bombs is released the switch is automatically returned to its im'tial position.

In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:

FTGURE l is a diagrammatic view showing an intervalometer containing one embodiment of our invention.

FIGURE 2 is a sectional elevation of the intervalometer shown diagrammatically in FIGURE 1.

FIGURE 3 is a sectional view taken along the line 33 of FEGURE 2.

FiGURE 4 is a fragmentary sectional view with parts broken away taken along the line 4-4 of FIGURE 2.

FIGURE 5 is a diagrammatic view showing an electrical circuit used in our invention.

Referring now to the drawings, a housing 10 may be secured to the aircraft at the bombardiers position. The housing supports a shaft 12 to which is secured a control knob 14. The control knob 14 is adjustably pinned by pin 16 to a second knob 18 which is in turn adjustably pinned by pin 21) to the housing 16. Any other suitable means such as frictional engaging means may be employed to secure knob 18 adjustably to the housing 10, as will be apparent to those skilled in the art. A frictional collar 19 made of rubber or the like carried by the knob 18 is adapted to engage the housing with sufficient friction to hold the knob 18 in place. The knob 14 controls the bomb spacing and the knob 18 controls the number of bombs which are to comprise the stick.

Referring now to FIGURE 2, it will be seen that the knob 14 is secured to the shaft 12 by a pin 22. The pin 16 is normally urged into locking position with the knob 18 by the spring 24. By pulling pin 16 to the left knob 14 will be released from knob 18 and may be positioned with respect thereto.

The knob 18 is normally secured to the housing 16 by the pin 20 which is normally urged to the right in FIG- URE 2 by the spring 26. By pulling pin 2;} to the left against the action of spring 26 the knob 18 may be rotated with respect to the housing 10.

Secured to the knob 18 for rotation therewith is a sun gear 28. As shown in FIGURE 2, the sun gear 28 is attached to the knob 18 by means of screws 30 and pins 32. A second sun gear 34 is carried for relative rotation with respect to the shaft 12. Cross-connecting members 36 extend between the sun gears 28 and 34 to form a drum so that both sun gears will turn as a unit. A plurality of gears 38, 46, 4-2, 44, 46, 48 and 50 are mounted on the shaft 12, of which only gear 50 is keyed to the shaft 12 by means of key 52. All of the other gears 38, 4-0, 42, 44, 46 and 48 are mounted on shaft 12 for relative rotation with respect thereto. A shaft 54 is carried by the sun gears 28 and 34 parallel to the shaft 12 and for rotation in the bearings formed in the sun gears. Secured to this shaft by a plurality of keys 56 are a plurality of gears 58, 69, 62, 64, 66, 68 and 70 which gears mesh respectively with gears 38, 40, 42, 44, 46, 48 and 50. It will be observed that the gears carried by the shaft 12 decrease in diameter progressively from the sun gear 28 toward the sun gear 34 while the meshing gears increase in diameter progressively from sun gear 28 toward sun gear 34. The gear ratios are such that when gear 38 moves an angle x with respect to the sun gear 28, gear 48 will rotate through an angle 2x with respect to the sun gear, gear 42 will rotate through an angle 3x, gear 44 will rotate through an angle 4x, gear 46 will rotate through an angle 5x, gear 48 will rotate through an angle 6x, while gear 50 will rotate through an angle 7x. In the drawings we have shown an intervalometer adapted to control eight bombs in which eight bombs is the maximum number of bombs which may comprise a stick. It

is to be understood, of course, that any number of gears may be used to control any suitable number of bombs. By way of illustration and not by Way of limitation, let us assume that gear 38 is provided with thirty-six teeth and gear 58 is provided with nine teeth, the gear 40 will have thirty-two teeth and its meshing gear 60 will have sixteen teeth, gear 42 will have twenty-eight teeth and its meshing gear 62 will have twenty-one teeth. Gear 44 will have twenty-four teeth and its meshing gear 64 will have twenty-four teeth. Gear 46 will have twenty teeth and its meshing gear 66 will have twenty-five teeth. Gear 48 will have eighteen teeth and its meshing gear 68 will have twenty-seven teeth. Gear 50 will have sixteen teeth and its meshing gear 79 will have twenty-eight teeth. It will be readily appreciated, therefore, that if gear 56 is rotated by means of knob 14 through an angle 7x, gear 48 will move through an angle 6x, gear 46 will move through an angle x, gear 44 will move through an angle.

4x, gear 42 will move through an angle 3x, gear 40 will move through an angle 2x and gear 38 will move through an angle x. This motion is achieved by the rotation of gear 50 which is secured to the shaft 12. It meshes with gear 70 which is secured to the shaft 54 along with all of the other gears 68, 66, 64, 62, 6t] and 58 so that when gear 76 rotates these gears will rotate to drive the gears with which they are in engagement through the predetermined angles determined by the gear ratios.

An arm 72 is secured to the gear 38 in any suitable manner for rotation therewith. A rod 74 passes through an opening at the end of the arm 72. A planetary gear 76 is carried by one end of the rod 74 in engagement with the sun gear 28 and a corresponding planetary gear I 78 in engagement with the sun gear 34 is carried by the other end of the rod 74. The planetary gears 76 and 78 are secured to the rod 74. The arrangement is such that the two planetary gears 76 and 78 and the rod 74 form a parallel motion arrangement so that when the arm 72 is moved by the gear 38, the rod 74 will be positioned around the sun gears, that is, around the drum formed by the sun gears 28 and 34 and the interconnecting members 36. In a similar fashion, an arm 80 is secured to the gear 40, an arm 82 is secured to the gear 42, an arm 34 is secured to the gear 44, an arm 86 is secured to the gear 46, an arm 83 is secured to the gear 48, and an arm 90 is secured to the gear St). The arm 80 engages a rod 92 in a manner similar to the engagement of the rod 74 by the arm 72. In a similar fashion, the arm 82 engages a rod 94, the arm 84 engages a rod 96, the arm 86 engages a rod 98, the arm 38 engages a rod 100 and the arm 94 engages a rod 102. A pair of planetary gears 'is secured to each of the rods in a manner similar to the planetary gears 76 and 78. The sun gear 23 carries at a predetermined point a display numeral 1 indicated by the reference numeral 161. The rod 74 carries a display numeral 2 indicated by reference numeral 104. In a similar fashion the rod 92 carries a display numeral 3, the rod 94 carries a display numeral 4, the rod 96 carries a display numeral 5, the rod 98 carries a display numeral 6, the rod 100 carries a v the display numerals may be made to appear by rotating the sun gear drum by means of the knob 18. After the predetermined bomb spacing has been set by means of knob 14 the rods will be positioned around the sun gears at equally spaced intervals representing the desired spacing and the display numerals will be carried therei with. The setting of a predetermined display numeral in the window 198 determines the number of bombs to comprise the stick. For purposes of simplicity we have shown an intervalometer capable of releasing eight bombs, but it is to be understood, however, that any suitable number of rods and gears may be employed according to the number of bombs to be used in a stick, the rods and pairs of gears being one less than the number of bombs. It will be apparent that after the bomb spacing has been set the rotation of the drum will rotate all of the rods together with the sun gears without disturbing the spacing.

The other ends of each of the rods project slightly beyond the sun gear 34. One of these projections is shown in FIGURE 4 designated by the reference numeral 110. A pair of the projections 119 appear in FIGURE 2. These projections act as cams to actuate an intervalometer switch 250 adapted to release the bombs.

A gear wheel 112 is adapted to be driven as a function of ground speed. A lever 114 is carried by the gear Wheel 1112 for rotation therewith and is pivoted about a fulcrum pin 116 carried by the gear 112. A follower roller 118 is carried by the lever 1'14 adjacent the locus of the cams formed by the ends of the rods 74, S 2, 94, 96, #8, 100 and 162. A guide roller 119 is carried by the gear 112 to balance the thrust of the roller 118. The guide roller engages a ring 121 carried by the sun gear 34. A switch operating lever 129 is pivoted about a pin 122 carried by the wheel 112. Its upper end is connected by pin 124 to the lower end of the cam operated lever 114. As will be seen by reference to FIGURE 2, the arrangement is such that as the cam operated lever 114 rotates in a clockwise direction the switch operating lever will rotate in a counterclockwise direction. The movement to the right, as viewed in FIGURES l and 2, of the lower portion of the switch operating lever 120 will complete a circuit to operate the bomb dropping mechanism to release one bomb by moving the switch member 251 to the right against the action of spring 253 to make contact at switch contact 250. This circuit will be described more fully hereinafter with reference to FIGURE 5.

The rotation of the drum formed by sun gears 28 and 34 is communicated by a stub shaft 126 to a bevel gear 128 which meshes with a bevel gear 130. The rotation of the drum in the setting of the number of bombs to be dropped in the window 168 automatically performs the multiplication of the bomb spacing times the number of bombs, thus giving stick length. The ratio between movement of gear 128 and the final drive in the computer is such as to give a release advance of one-half stick length to the bombing computer in which true air speed, drift, ballistic, bomb trail, altitude and other pertinent factors are combined. The output of the computer drives a shaft 134 through a control equipped with a reversing gear and clutches housed in casing 136. The output of the control, determined in direction by the clutches and in speed by the output of the computer, drives shaft 138 carrying a pinion 146 which meshes with the gear 112. A switch box 1 42, supported by the housing 10, carries a normally closed limit switch 144. This switch acts as the last bomb switch and is adapted to de-energize the bombing circuit and energize the return clutch engaging solenoid, as will be described more fully hereinafter. A lug 145 is carried by the gear 112, as can readily be seen by reference to FIGURES l and 4. When the return clutch is engaged, the gear 112 is driven in a counterclockwise direction in FIGURE 1 until the lug 135 carried by the gear 112 engages a stop member 137 carried by the sun gear 34. At this time the return clutch will slip, maintaining the lug 135 against the stop member 137. As the position of this stop member is changed the gear 112 will follow, always maintaining the lug 135 against the stop 137 when the return clutch is in engagement. In this position the roller 118 of the intervalometer switch will be positioned against a lug 139 formed on the sun gear acting as a cam of fixed position closing the intervalometer switch. This cam represents the 1" bomb, and the cam operated switch is always in a position to drop the bomb whenever the release switch is actuated, as will be pointed out more fully hereinafter. When the release switch is operated the forward clutch is energized and the gear 112 will then rotate in the direction of the arrow in FIGURE 1, that is, in a clockwise direction continuing to drop bombs as the cams carried by the rods positioned as described above act to energize the bomb dropping mechanism. The selection of the number of bombs in the stick automatically shifts the position of the lug 145 since the gear 112 is automatically positioned. The arrangement is such that immediately after the last bomb is dropped the circuit closed by switch 144 will be opened. If, for example, five bombs are to comprise the stick the lug 145 will actuate the switch immediately after the fifth bomb is dropped and before the sixth bomb reaches a position for release. This can be best understood from the circuit shown in FIGURE 5, to which reference is now had.

Potential from any suitable source is impressed upon conductor 200 and conductor 203. A relay winding 214 is adapted to attract armatures 216 and 218 whenever it is energized. Since armature 218 is normally in the position shown in FIGURE 5, current will flow from the conductor 203 through armature 218 to contact point 220, through conductor 222 through return clutch relay winding 210 to ground 212, thus energizing the return clutch relay. This will engage the return clutch to drive the gear 112 in a counterclockwise direction, as viewed in FIGURE 1 to bring the lug 145 against the stop 137. Let us now assume that a bomb spacing of two hundred feet is to be chosen. The pin 16 is pulled outwardly and the knob 14 rotated to bring its pointer 15 to the two hundred calibration mark of the calibrations -17 formed on the knob 13, as can be seen by reference to FIGURE 1. This will space each adjacent pair of rods 74, 92, 94, 96, 98, 100 and 102 around the sun gears 28 and 34 in a clockwise direction through an interval representing two hundred feet. Let us assume that five bombs are to comprise the stick. The pin 20 is then released and the knob 18 is rotated in a counterclockwise direction to bring the signal in a position opposite the window 108. As this is done the stop 137 will move in a counterclockwise direction and since the return clutch is engaged the gear 112 will rotate in a counterclockwise direction to maintain the lug 135 against the stop, always in a position so that the roller 118 closes the release switch for the l bomb through its contact with the fixed cam 139 representing the 1 bomb.

Referring again to FIGURE 5, let us assume that a bombing run is to made on the target. The knob 202 which is secured to the arming switch armature 201 is moved upwardly, thus completing a circuit across contact points 224 and 226. Current will then flow through the holding relay winding 203 maintaining the armature 201 in armed position, the current flowing through conductor 204, conductor 205, through the normally closed last bomb switch 144 to ground 206. The bombardier has a normally open release switch 228 adjacent his position. This switch may be automatically closed by the bombsight mechanism or manually by the bombardier when the bombsight indicates the stick is to be dropped. When switch 228 is closed current will flow from contact point 226 through conductor 223 across switch 228 through conductor 230 through relay winding 214 through conductor 205 through last bomb switch 144 to ground 206, thus energizing the winding 214 and attracting armatures 216 and 218. The upward movement of armature 218 will open the circuit through return clutch relay winding 210 and make a circuit with contact point 240 to energize the forward clutch relay winding 242. When this occurs a current will flow from conductor 208 through armature 218 to contact point 240 through conductor 244 through relay winding 242 to ground 212, thus energizing the forward clutch relay which engages the forward clutch and drives the gear 112 in a clockwise direction, as viewed in FIGURE 1. At the same time, the armature 216 will be moved upwardly to make contact with the contact point 246 providing a holding circuit to maintain the relay 214 in an energized condition. The release switch 228 is only momentarily closed and initiates the action. After the release switch 228 is opened, having been closed to energize initially the winding 214, current will then flow from conductor 223 through conductor 248 through armature 216 to contact point 246, thence through relay winding 214 through conductor 205 through last bomb switch 144 to ground 206. The cam operated intervalometer switch is indicated by the reference numeral 250. Every time this switch closes current will flow through conductor 230 through conductor 231' through switch 250 through the bomb release relay winding 249 to ground 247. The energization of the relay winding 249 operates the bomb releasing mechanism to release one bomb. This bomb releasing mechanism is not shown and may be any suitable bomb releasing mechanism known to the art. As the gear 112 continues its rotation in a clockwise direction it will successively release bombs at the correct predetermined interval carrying around with it the lug 145. Just after the fifth bomb is released in the assembly mentioned above, the lug contacts the lower arm 143 of the switch 144 and opens the circuit made by this switch. In FIGURE 5 it will be seen that this interrupts the circuit to ground 206. When this occurs the holding relay 2% is deenergized permitting the armature 201 to drop thus de-energizing the conductor 223 which deenergizes the relay 214 permitting the armatures 216 and 218 to drop. At this point the cam operated intervalometer switch is rendered ineffective and the return clutch is automatically re-energized, driving the gear 112 in a counterclockwise direction back to its stop position.

It will be seen that we have accomplished the objects of our invention. We have provided an intervalometer in which the number of bombs to comprise the stick may be varied within wide limits and in which the bomb spacing may likewise be varied and in which the individual bombs comprising the stick are automatically dropped as a function of the output of the computer in which ground speed and other control functions are fed. Our intervalometer automatically determines the length of the stick and release advance distance is automatically computed and fed to the computer. Our intervalometer is very flexible, simple in construction, and sure in operation.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is therefore to be understood that our invention is not to be limited to the specific details shown and described.

Having thus described our invention, what we claim is:

1. An intervalometer for controlling the successive release of a plurality of missiles from an aircraft, including in combination a housing, a drum, means for rotatably positioning said drum within said housing, a fixed cam carried by said drum, a plurality of movable cams carried by said drum, means for positioning said cams to forms equal intervals therebetween around said drum, means for indicating the position of said drum, a missile releasing means, a cam operated switch associated with said cams for controlling said releasing means, means for operating said switch, and means for rotating the switch operating means at a predetermined speed whereby successively to operate said missile releasing means to release the missiles at predetermined intervals governed by the speed of rotation of said cam operated switch operating means and the intervals between said cams.

2. An intervalometer as in claim 1, in which said drum is formed by a pair of sun gears, and means interconnecting said sun gears to turn in unison.

3. An intervalometer as in claim 1, in which said means for positioning said cams to form equal intervals therebetween comprises a pair of sun gears carried by said drum, a shaft coaxial with said drum, a parallel shaft carried by said drum spaced from said axial shaft, a plurality of intermeshing gears of progressively varying ratio carried by said shafts, one of said gears carried by said axial shaft being secured thereto, the remaining gears carried by said axial shaft being positioned for relative rotation with respect thereto, the gears carried by said parallel shaft being secured thereto for rotation therewith, a plurality of radially extending arms carried by said axial shaft gears, a plurality of elongated members secured respectively to said radial arms and extending parallel to said shafts, planetary gears carried by said elongated members, the movable cams being carried by said elongated members, and means for rotating said axial shaft to position said radially extending arms, the gear ratios being such that each arm will move a multiple of the angular displacement of the first movable cam from said fixed cam whereby the distance between cams will always remain equal.

4. An intervalometer as in claim 1, including in combination a pair of sun gears carried by said drum, a plurality of planetary gears meshing with said sun gears, elongated members extending longitudinally of said drum between planetary gears, said movable cams being carried by said elongated members, said means for indicating the position of said drum comprising signals carried by said elongated members, and a window formed in said housing through which said signals may be viewed.

5. An intervalometer as in claim 1, including in combination a gear mounted for rotation coaxially with said drum and positioned adjacent the cams, said switch operating means being carried by said gear, a stop member carried by said drum, a coacting stop member carried by said gear, means for driving said gear to position said stop members against each other, said switch operating means being in position adjacent said fixed cam when said stop members are against each other closing said cam operated switch to drop said first missile upon the energization of said missile releasing means.

6. An intervalometer as in claim 1, including in combination a gear mounted for rotation coaxially with said drum and positioned adjacent the cams, said switch operating means being carried by said gear, a stop member carried by said drum, a coacting stop carried by said gear, means for driving said gear to position said gear stop against said drum stop member, said switch operating means being in position adjacent said fixed cam when said gear stop is against said drum stop member closing said cam operated switch to drop said first missile upon the energization of said missile releasing means, and means for driving said gear in an opposite direction upon the energization of said missile releasing means whereby said switch operating means will be moved past said cams successively to operate said cam operated switch to release missiles in succession.

7. An intervalometer as in claim 1, including in combination a gear mounted for rotation coaxially with said drum and positioned adjacent the cams, said switch operating means being carried by said gear, a stop member carried by said drum, a coacting stop carried by said gear, means for driving said gear to position said gear stop against said drum stop member, said switch operating means being in position adjacent said fixed cam when said gear stop is against said drum stop member closing said cam operated switch to drop said first missile upon the energization of said missile releasing means, means for driving said gear in an opposite direction upon the energization of said missile releasing means whereby said switch operating means will be moved past said cams successively to operate said cam operated switch to release missiles in succession, a last missile switch adapted to de-energize said missile releasing means and to drive said gear to a position seating said gear stop against said drum stop, a second switch operating means carried by said gear adapted to operate said last missile switch, the construction being such that after the last missile has been dropped said second switch operating means will open said last missile switch to de-energize said missile dropping means and to reverse the direction of rotation of said gear.

8. An intervalometer as in claim 1, including in combination a gear, said switch operating means being carried by said gear, said means for rotating said switch operating means at a predetermined speed comprising means for rotating said gear, and means responsive to the rotation of said drum for indicating a function of the length of the stick of missles being dropped.

9. An intervalometer including in combination a plurality of equally spaced cams, a cam operated switch, means for operating said switch, means for rotating said switch operating means adjacent said cams as a function of the ground speed of an aircraft, bomb releasing means controlled by said switch, and means for adjusting the position between cams whereby to change the interval at which said switch is operated.

10. An intervalometer including in combination a plurality of equally spaced cams, a cam operated switch, means for operating said switch, means for rotating said switch operating means adjacent said cams as a function of the ground speed of an aircraft, bomb releasing means controlled by said switch, means for adjusting the position between cams whereby to change the interval at which said switch is operated, a last bomb switch adapted to de-energize said bomb releasing means, means responsive to the movement of said switch operating means for actuating said last bomb switch, and means for adjusting the relative position of said responsive means with respect to said last bomb switch for varying the number of bombs in a stick.

References Cited in the file of this patent UNITED STATES PATENTS 2,359,967 Brown Oct. 10, 1944 2,396,197 Peterson Mar. 5, 1946 2,428,581 Peterson Oct. 7, 1947 2,504,492 Brown Apr. 18, 1950 

